Water Supply in the Field

Objectives

Importance of safe water in the fieldResponsibilitiesDefinitionsRules for water useTypes of sources and considerationsTypes of water treatment and containers

Medical Importance

Safe water is essentialPrevents water borne diseasesIncreases mission effectiveness

Responsibilities

Unit Commander: Overall responsible for providing safe water for drinking and hygiene.Preventive medicine:

In charge of testing water Ensures training for personnel on water discipline

Definitions

Palatable Water: Water that looks, smells, and taste good.Potable water: Water that is safe for human consumption.Water treatment: Water that is treated chemically to improve its quality.Disinfection: A process of killing infectious agents outside the human body by direct exposure to chemical or physical agents.

Definitions

Chlorination: A treatment process that combines the water with chlorine or chlorine compound.Chlorine Dosage: The total amount of chlorine or chlorine compound added to a given amount of water.Chlorine Demand: The amount of chlorine dosage used or consumed by substances in the water.

Chlorine Residual: The amount of chlorine left in the water after the chlorine demand has taken effect.Parts per Million (PPM): The parts of chlorine present in a given volume of water (concentration).

This value may also be expressed in Milligrams per Liter (Mg/L).

Definitions

Rules for Water Use

Drink approved water only. Prevent water waste. Protect water sources with good sanitary

practices.

Water Source Types and Considerations

Surface Water: Streams, rivers, ponds, and lakes.Most commonly selected.

Ground water: Wells and springsCostly to obtainDifficult to determine its quantity

Rainwater, Ice, Snow, Seawater

Surface Water

Ground Water

Considerations

The military situation (Combat situation compared to training.)The Quantity needed (Will the unit be here for 6 months or 2 weeks.) The accessibility to the source. (Is the water easy to reach)The general quality of the source. The equipment available for use (Chlorine, purification unit)

Water Treatment

Methods: Coagulation/Sedimentation, Filtration, Disinfection, Chemical treatment (Chlorine or Calcium Hypochlorite), BoilingChlorination of water containers

Water Treatment Chart

Inspection of 18hl Water Trailer

Inspect:ContainerManholeSpigotsDrains

Chlorine Residual Monitoring Kit

Components:100 calcium hypochlorite ampoules 150 diethyl-p-phenylene diamine (DPD) #1 tablets One plastic color comparator

Procedure For Monitoring Residual

Wash your hands.Flush the taps of the 400-gallon water trailer.Triple-rinse the color comparator.Fill the comparator with water.Add a DPD #1 tablet.Wait one minute.

Place your thumb over the opening and invert the comparator three times to ensure that the DPD #1 tablet is completely dissolved.Compare the color of the water in the right window to the color in the left window.Location where color break can be seen is where residual is measured

Procedure For Monitoring Residual

Monitoring the Chlorine Residual

Emergency field water requires a chlorine residual of 5 ppm or a chlorine residual established by medical or engineering.

Color Break

Approx. 2-3ppm

Re-chlorinating a Water Buffalo

Mix 1 MRE spoonful of Calcium hypochlorite from the 6-ounce bottle, or use 4 ampoules with one-half canteen cup of water.Thoroughly mix the slurry and then add it to the water in the trailer.Mix the solution with a clean stick or other clean device and flush the four taps.Wait 10 minutes, flush the taps again, and check the chlorine residual.

Re-chlorinating a Water Buffalo

When chlorine residual reaches 1 ppm, wait 20 minutes and release water.

Re-chlorinating a 22L Water Can

Re-chlorinating a 22L Water Can

Add 1 ampoule of calcium hypochlorite to a ½ canteen cup of water and stir the slurry solution.Add approximately ½ of the solution to one 5-gallon can.Shake the container and wait 10 minutes. Loosen the cap and invert the can to let some treated water flow over the threads of the can.Wait an additional 20 minutes, for a total contact time of 30 minutes.

Disinfecting a 1L Canteen With Iodine Tabs

Disinfecting a 1L Canteen With Iodine Tabs

Drop two iodine tablets into a canteen filled with water and wait 5 minutes for the tablets to dissolve.Cover the canteen and shake it.Loosen the canteen cap and invert the canteen to allow the treated water to flow across the threads of the canteen neck.Wait a minimum of 30 minutes before consumption.

Disinfecting Canteen with Calcium Hypochlorite

Disinfecting Canteen with Calcium Hypochlorite

Dissolve the contents of 1 ampoule in ½ canteen cup of water to make a slurry.Fill an NBC compatible canteen cap or ½ non-NBC cap with the slurry. Pour the cap contents into the canteen and wait 5 minutes.Cover the canteen and shake it.Loosen the cap and invert the canteen to allow treated water to flow across the threads of the canteen neck.Wait a minimum of 30 minutes before consumption.

Boiling

Use in emergencies ONLY.Boil water for 5-10 minutes.

Bottled Water Operations

Use when operations are short or source can not be obtained and resources available and waste disposal proper.It is important to protect open bottles of water from secondary contamination.

Review Questions

1. What is the importance of clean/safe water?2. What is the difference between disinfection and

chlorination? 3. What is the difference between Ground and Surface

water?

4. How many ppm of chlorine residual is required for emergency field water?

5. When re-chlorinating a water buffalo, how many ppm of chlorine residual must be reached prior to release?

6. When do you boil water for use?

Review Questions